Back in the good ol' days you could get away with an open sunroof (sans mesh). Or at least that's what we did. The letter of the law (below) describes an option including a closed original sunroof.
You, sir, are describing a moon roof (and not a t-top which is also explicitly described below). So either you get off scott free or your must have it sealed in some form or fashion.
Personally I would hire a lawyer to see if there's some way around the rules. (I kid!1)
"# 3.20: No Open Sunroofs: All sunroof openings must be covered by either the original sunroof panel; a new panel securely fixed into place; or securely fixed mesh with openings no larger than 1/2-inch each.
# 3.21: Open T-Tops and Convertibles: Arm restraints are required when driving an open T-Top or convertible."
Greg
Quattro Libre '84 Audi (Lemons South '08)
The Slammer '87 Milano (Lemons South '09)
The Slammer '87 Milano (Southern Discomfort '10)